Application Ser. No. 11/422,420 referred to above, discloses and claims a pin and grommet fastener with high fastening strength, used in attaching an airbag to a vehicle body. The present invention is a further development of the invention of that application.
Pin and bush (grommet) fasteners for joining panels and/or for mounting various types of members on panels are well known. See, for example, Japanese Utility Model Laid-Open Publication No. 05-050130; Unexamined Japanese Utility Model Application Publication No. 1-85509; United States Patent Application Publication No. US 2005/0062263; Japanese Patent Laid-Open Publication No. 2000-240624; U.S. Pat. No. 6,910,840; and U.S. Pat. No. 6,932,552. For certain applications, for example attaching a curtain shield airbag to a body panel of a vehicle, it is desirable that such fasteners be strong enough to resist detachment forces in both vertical and horizontal directions with respect to workpieces.
The invention disclosed and claimed in U.S. application Ser. No. 11/422,420 provides an improved pin and bush (grommet) fastener that can be fastened to workpieces, such as panels, with high enough fastening strength to resist both vertical and horizontal detachment forces. The invention provides a fastener (clip) that can provide high fastening strength to a thin panel and that effectively prevents deformation of the thin panel. More particularly, the invention can provide secure attachment of a curtain shield airbag to a body panel of a vehicle.
In a preferred embodiment of the invention disclosed and claimed in U.S. application Ser. No. 11/422,420, a fastener comprises a pin having a head and a plurality of legs depending from the head, and a grommet having a flange and a shank depending from the flange. In use, the pin is pushed into the grommet. The shank of the grommet has longitudinal slots for receiving respective legs of the pin when the pin is pushed into the grommet, and has resilient pawls for engaging corresponding edge regions of a mounting hole in a workpiece (e.g., a car body panel) when the grommet shank is inserted into the mounting hole. The grommet shank has a strong central axial column, the cross-section of which occupies most of the cross-section of the grommet shank. When the pin is fully inserted into the grommet shank, legs of the pin engage the axial column of the grommet and also engage respective resilient pawls of the grommet to prevent the pawls from moving inwardly of the grommet shank. The legs also fill out portions of the grommet shank cross-section not occupied by the axial column. When the grommet shank has a polygonal cross-section profile, for example, and is inserted into a polygonal profile hole, the cross-section of the grommet shank matches the profile of the hole. By virtue of the invention, high fastening strength is achieved that strongly resists axial and transverse detachment forces applied to the fastener.
In accordance with the invention described and claimed in application Ser. No. 11/422,420, the pin can be pushed into the grommet to a temporary connection position, at which the legs of the pin do not impede inward movement of the pawls with respect to the shank of the grommet, and can be pushed in farther to a permanent connection position, at which the legs block inward movement of the pawls.
As further described and claimed in application Ser. No. 11/422,420, such fasteners are used in an assembly that includes an attachment member for an airbag and that mounts the airbag on a body panel of a vehicle.